Trial Information

A Phase 3, Randomized, Double-Blind, Placebo-Controlled Study of Abiraterone Acetate (CB7630) Plus Prednisone in Patients With Metastatic Castration-Resistant Prostate Cancer Who Have Failed Docetaxel-Based Chemotherapy

Abiraterone acetate is a steroidal irreversible inhibitor of CYP17 (17α hydroxylase/C17,
20-lyase), blocking 2 important enzymatic activities in the synthesis of testosterone. The
goal of this study is to compare the clinical benefit of abiraterone acetate plus prednisone
with placebo plus prednisone in patients with metastatic castration-resistant prostate
cancer (CRPC) who have failed one or two chemotherapy regimens, one of which contains
docetaxel. All patients involved in the study will be randomized (assigned by chance) into
one of two arms and will not know what study drug is being given to them. Study drug
randomization allocation will be 2:1 (abiraterone acetate: placebo). The study will be
conducted in the United States, Canada, Australia, and the EU. The study will consist of
screening, treatment, and follow-up. In this study, patients will receive study treatment
(abiraterone acetate or placebo) plus prednisone until progression of clinical disease.
Follow-up will continue until patient dies, is lost to follow-up, or withdraws informed
consent. After providing written informed consent, patients will have screening procedures
completed to determine eligibility. Safety evaluations at the screening procedure will
include a physical examination, vital signs, and clinical blood laboratory tests, ECG,
radiographs, urine tests, and recording of any adverse events including details of current
prostate cancer symptoms. Patients will be asked to use a method of birth control with
adequate barrier protection as determined to be acceptable by the principal investigator and
sponsor during the study and for 13 weeks after last study drug administration.

Study medication, abiraterone acetate,is an oral (by mouth) medication to be administered as
four (4) 250mg abiraterone acetate tablets or 4 placebo tablets to be taken at least one
hour before or two hours after a meal anytime up to 10PM everyday. Prednisone will be
administered as 5mg orally twice a day for both groups. Each cycle will be 28 days. Study
treatment will continue until disease progression as determined by investigator or when the
patient meets criteria for withdrawal from study.